Standardized business documents are a prerequisite for successful electronic information exchange in inter-organizational systems. These documents are typically defined through Standard Developing Organizations (SDOs) such as the United Nations Centre for Trade Facilitation and eBusiness (UN/CEFACT). In today´s highly dynamic environment with ever-changing market demands, SDOs are confronted with the need to constantly evolve their standardized business documents based on the needs of business partners utilizing these documents. However, the business document development process between SDOs and business partners is currently lacking efficient collaborative support. In this position paper, we present (i) a reference model supporting hierarchical, collaborative and cross-organizational business document modeling, (ii) a conflict resolution model to find a consolidated version of a new business document model as well as (iii) our vision of a Configurable Collaboration-Aware Online Model Repository.